Keying choker



Oct. 1, 1929.

M. osNos 1,730,160

KEYING CHOKER Filed Dec. 1, 1925 H16 H FEEQUENCY CON D UCTOK- IHSULATOK IRON HIGH FREQUENCY CONDUCTOR lNVENTOR MENDEL osuos A TORNEY Patented Get. 1, 1929 Fit MENDEL OSNOS, OF BERLIN, GER-MANY, ASSIGNOR 'lO GESELLSCHAFT DBAT-I'ILOSE TELEGRAEI-IIE III. B. 1-1., 01 BERLIN, GERMANY, A CORFORATION 0F GERMANY KEYING CHOKER Application filed December 1, 1925, Serial No. 72,458, and in Germany December 5, 1924.

In installations utilizing extra high frequency currents, the suggestion has been made to use an iron-enveloped conductor as the keying or telephony modulator. Such a device, in the presence of frequencies as here coming into consideration, possess a considerable inductive and ohmic resistance, which may be neutralized by saturating the iron by a sufficiently large superposed auxiliary field, preferably a direct current field.

In this scheme, however, the difficulty is encountered that, if the controlling current is fed into the same conductor as the high frequency current, the two currents mustapproximately be of the same order of magnitude, while, on the other hand, it is desirable to work with by far smaller controlling currents.

Now, this diiiiculty is obviated according to the invention by exciting the iron body surrounding the high frequency conductor with a separate control current coil producing an auxiliary field of two or more poles.

The accompanying drawing illustrates two embodiments of this idea, Fig. 1 referring to the two-pole excitation of the auxiliary field, while Fig. 2 shows an arrangement for multipole excitation.

Referring to the figures, (1 stands for the high frequency conductor, Z) the iron body enveloping the same, while 0 is the controlcurrent coil. It is preferable to build the latter of a bare conductor arranged upon a carrier consisting of porcelain or a similar refractory insulator.

Having thus described my invention, 1 claim is 1. In a high frequency modulation system, a high frequency conductor of non-magnetic material, a magnetic material having a portion thereof enveloping said conductor and another portion thereof extending outwardly from the portion enveloping said conductor and forming a closed magnetic path with said first named portion, and means indewhat pendent of said high frequency conductor associated with said extending portion of said magnetic material for controlling the magnetic saturation of said material and modulating the said high frequency flowing through said high frequency conductor thereby.

2. In a high frequency modulation system a path of high frequency currents, an iron body enveloping said high frequency current path and having a portion extending outwardly therefrom and forming a closed circuit for magnetic currents, control current means associated with said extended portion MENDEL OSNOS. 

